Differences in respiratory-related physiological signal features among diverse histological subtypes and clinicopathology stages of lung cancers

Abstract

Objectives: Lung cancer (LC) is a highly heterogeneous disease characterized by complex clinical repercussions, diverse histological subtypes, and clinicopathological stages. However, the relationship between physiological features and subtypes/stages of LCs remains unclear. This study aims to compare the differences in respiratory-related physiological features among LCs with diverse subtypes/stages.

Materials and Methods: Respiratory-related physiological signals, including airflow, transthoracic impedance, surface diaphragm electromyography, and lead II electrocardiogram, were recorded from 164 LCs and 80 healthy controls (HCs) in a resting state. Fifteen features obtained from these signals were compared between LCs and HCs, compared among subtypes of adenocarcinomas (ADC), squamous carcinomas (SCC), and small cell lung carcinomas (SCLC), and compared among stages of I, II, III, and IV.

Results: There were no statistical differences in baseline characteristics between LCs and HCs except that LCs had a higher smoking rate. Of all features in SCLC and ADC, eight features in SCC were significantly lower than HCs. One feature across the three subtypes and 12 features between the two subtypes differed significantly. Three features in stages I and II, 13 in stage III, and all in stage IV were significantly lower than HCs. Two features in stage II, 9 in stage III, and 13 in stage IV were significantly lower than in their respectively earlier stages.

Conclusion: Compared with HCs, respiratory-related physiological signal features for LCs are significantly decreased, especially in the SCLC and ADC subtypes. These features also differ markedly among subtypes. Besides, the number of features that vary among stages increases as the LC progresses.